As the title suggests, the ability to create a league & lock the tiers above Rookie Only rather than just locking the entire league structure. This would mean that progression into the tiers of those leagues would need to be done via promotion through the ranks or at the league owners discretion through invites etc.
The main reason for suggesting this being to promote closer racing between teams who have developed together over the course of multiple seasons as well as increasing the community aspect of leagues as teams who have fought together in the various tiers in recent seasons would have formed rivalries/relationships with teams as they have progressed.
This could hopefully help to create closer communities of managers who feel a sense of achievement at reaching Elite by progressing through the various tiers of a competitive league structure rather than just joining a relatively inactive league & gaining promotion via default.
Whilst the pros & cons of such a system would need to be considered, this is something that shouldn’t be too difficult to implement?